In September the US Environmental Protection Agency (EPA) released its third and latest “contaminant candidate list” (CCL) — a roster of substances which are not now regulated in drinking water by the federal government but which EPA may consider for future regulation.

This new list (called “CCL 3”) consists of 116 substances of all types: inorganic chemicals, organic chemicals and living organisms.

Twice before, in 1998 and 2005, EPA produced similar lists, called CCL 1 and CCL 2 respectively. The lists are based on the idea that scientific knowledge about the effects of “emerging contaminants” (ECs) on humans and the environment doesn’t stand still. Also continuing to advance are detection methods for ECs and the technical and economic feasibilities for removing them.

Many in the point-of-use/point-of-entry (POU/POE) water treatment industry keep an eye on these lists, because they give manufacturers and dealers a preview of what future federal and state rules may require in the marketplace for treatment technologies.

A fast-changing picture
The concept of ECs has been around for some time, but this year, the new CCL 3 reflects major new developments, among them:

• Discoveries by researchers that ingredients in pharmaceutical and personal care products are now showing up in water sources and in treated drinking water. There have been suggestions, based on animal studies, that these substances could have adverse health effects on humans.

• Significant new attention by the news media to (and accompanying heightened public awareness of) drinking water quality throughout the United States. Notable are continuing investigations conducted by The Associated Press (AP) and The New York Times.

Science, government and industry have taken note. Over the past two years, water research institutions and trade associations have conducted seminars on “emerging contaminants.” State and local governments have set up programs for proper public disposal of unused pharmaceuticals.

Governments and water agencies have begun testing their treated water for pharmaceuticals in tap water, and some have begun posting the results for the public.

One major POU/POE manufacturer, Calgon Carbon Corp., has conducted this year a series of seminars across the US, all dealing with emerging contaminants and disinfection byproducts. Other companies have sponsored similar events.

Contaminant ‘rollover’
Each time a CCL is produced, EPA must determine which substances on the list should be regulated. Interestingly, EPA made no regulatory determinations from the 60-substance CCL 1 of 1998 and the 51-substance CCL 2 of 2005.

However, a CCL is still considered to be guidance for future federal drinking water regulation, and is a way for the government, scientists, environmentalists, water utilities and industry to focus on substances that, in their view, have a high priority for regulation. All of these stakeholders participate in a lengthy EPA process to suggest contaminants and draw up the next CCL.

A number of substances that appeared on CCL 1 in 1998 have been “rolled over” into CCL 2 and now CCL 3 — an indication that they’re still considered potentially harmful. Examples of some that appear on the new CCL 3 and were also on prior lists are adenoviruses (viruses that can cause respiratory and gastrointestinal illnesses), acetochlor (a weed-control herbicide), vanadium (a natural element), and cyanotoxins (produced by blue-green algae).

Other substances have been dropped because new information changes their potential risk factors, or they are no longer found at sufficient levels to make them practical to remove.

The new CCL 3 is different.

EPA and the stakeholders looked at 7,500 substances before coming up with the final list of 116 on the CCL 3. Perhaps due to new research and media attention, between the time EPA drew up a preliminary CCL 3 list in early 2008 and the final CCL 3 it published two months ago, it added 10 pharmaceuticals, one antibiotic and nine hormones to the list, as well as two disinfection byproducts, five microbes and a firefighting foam.

The full CCL 3 list of contaminants can be found at this EPA Web site: www.epa.gov/safewater/ccl.

Doors open for POU/POE
The POU/POE industry “can offer the most advanced technologies available for dealing with endocrine-disrupting, pharmaceutical and personal care product residues in drinking water,” says Joe Harrison, technical director of the Water Quality Association (WQA). “We welcome the EPA benchmarks to guide our product development and performances in this new emerging area.”

Harrison says there’s no single POU/POE technology that can address all emerging contaminants. He says, “It appears that reverse osmosis (RO), activated carbon blocks, and advanced oxidation, such as is achieved by combining in various degrees hydrogen peroxide, ultraviolet light and/or ozone … may show effectiveness in treating many of these.”

WQA has proposed a list of 17 substances, not all of which are on the CCL 3, that could be targeted for developing new product performance standards (sidebar, right).

In the labs
Manufacturers and technology developers are taking the cue. One example is Norit Filtrix, a Netherlands-based company with US headquarters in Rockford, IL. The company is a producer of water treatment products for many applications, including POU/POE.

“We consider the United States to be a front-runner in regulating these emerging contaminants,” says Frank van Heusden, Norit Filtrix product marketing manager. “We are particularly looking into the endocrine-disrupting chemicals,” he says, explaining that his company is now actively researching how municipal and POU/POE systems could reduce or remove such chemicals.

One traditional treatment technology that might expand its role in the marketplace for EC treatment is activated carbon, according to van Heusden. “Activated carbon can do a lot,” he says. “It’s a technology that’s on the way back.” But he adds that activated carbon, like every technology, “is not magic. … It can’t do everything.”

Chantel Friedrich, Norit Filtrix’s business development manager for North America, and van Heusden note that Norit Filtrix is also among companies looking at EC solutions across a spectrum of membrane technologies, from microfiltration to RO.

ECs ‘out of the blue’
Steve Via, regulatory affairs manager for the American Water Works Association (AWWA), the trade group for public water system professionals, notes that some substances in this new group of ECs are “coming out of the blue” and are being analyzed at the parts-per-trillion (nanograms per liter) level.

Via says a careful process of determining true health risks and the feasibility of treatments must occur before EPA can set new rules, and before public water systems or consumers can decide which removal methods should be used. He observed that contaminants for which there is the greatest amount of information are the ones more likely to be regulated by EPA.

In the meantime, WQA’s Harrison has this advice: While many systems look promising for removing ECs, dealers shouldn’t make equipment performance claims without factual substantiation based on verifiable, scientifically valid testing.